Prior to the present invention, small crafts, such as dinghy or jet skis, had to be lifted by a hoisting device such as a crane or boom onto the side or deck of the mother boat for storage thereof. This was usually accomplished by a crane or hoisting mechanism that required several people to handle either manually or using a power winch. These types of lifting devices are costly and complex in design and require substantial reinforcement of the mother boat in order to make the deck strong enough to handle extreme loads required by the lifting crane. The L type cranes, the standard crane used by most small boaters, also are not suitable for lifting and storing small crafts onto yachts, for example less than 40 feet boats.
U.S. Pat. No. 4,878,450 sets forth an approach for trying to solve the problem by providing a boat-lifting device that is suitable for small vessels, is attached to the rear of the boat, and has a cradle that is vertically lowered to water level for transversely attaching a small dinghy thereto and raising the cradle vertically out of the water for storage.